[PATCH] rsi: fix integer overflow warning

From: Arnd Bergmann
Date: Thu Oct 05 2017 - 08:06:08 EST


gcc produces a harmless warning about a recently introduced
signed integer overflow:

drivers/net/wireless/rsi/rsi_91x_hal.c: In function 'rsi_prepare_mgmt_desc':
include/uapi/linux/swab.h:13:15: error: integer overflow in expression [-Werror=overflow]
(((__u16)(x) & (__u16)0x00ffU) << 8) | \
~~~~~~~~~~~~^~~~~~~~~~~~~~~~~
include/uapi/linux/swab.h:104:2: note: in expansion of macro '___constant_swab16'
___constant_swab16(x) : \
^~~~~~~~~~~~~~~~~~
include/uapi/linux/byteorder/big_endian.h:34:43: note: in expansion of macro '__swab16'
#define __cpu_to_le16(x) ((__force __le16)__swab16((x)))
^~~~~~~~
include/linux/byteorder/generic.h:89:21: note: in expansion of macro '__cpu_to_le16'
#define cpu_to_le16 __cpu_to_le16
^~~~~~~~~~~~~
drivers/net/wireless/rsi/rsi_91x_hal.c:136:3: note: in expansion of macro 'cpu_to_le16'
cpu_to_le16((tx_params->vap_id << RSI_DESC_VAP_ID_OFST) &
^~~~~~~~~~~

The problem is that the 'mask' value is a signed integer that gets
turned into a negative number when truncated to 16 bits. Making it
an unsigned constant avoids this.

Fixes: eac4eed3224b ("rsi: tx and rx path enhancements for p2p mode")
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
drivers/net/wireless/rsi/rsi_mgmt.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/wireless/rsi/rsi_mgmt.h b/drivers/net/wireless/rsi/rsi_mgmt.h
index b9d0802c1b0f..e21723013f8d 100644
--- a/drivers/net/wireless/rsi/rsi_mgmt.h
+++ b/drivers/net/wireless/rsi/rsi_mgmt.h
@@ -189,7 +189,7 @@
IEEE80211_WMM_IE_STA_QOSINFO_AC_BE | \
IEEE80211_WMM_IE_STA_QOSINFO_AC_BK)

-#define RSI_DESC_VAP_ID_MASK 0xC000
+#define RSI_DESC_VAP_ID_MASK 0xC000u
#define RSI_DESC_VAP_ID_OFST 14
#define RSI_DATA_DESC_MAC_BBP_INFO BIT(0)
#define RSI_DATA_DESC_NO_ACK_IND BIT(9)
--
2.9.0